Linked Life Data

11288932

Source:http://linkedlifedata.com/resource/pubmed/id/11288932

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-4-5
pubmed:abstractText
Maitotoxin is a potent water-soluble polyether toxin produced by the marine dinofiagellate Gambierdiscus toxicus. Although associated with increased calcium uptake, mobilization of internal calcium stores, and enhanced phosphoinositide metabolism, the primary molecular mechanism underlying its actions remains unclear. In this study, we evaluated the effects of maitotoxin (MTX) on the interaction of guanine nucleotides with G-protein alpha subunits. Equilibrium binding of the nonhydrolyzable GTP analog, GTPgammaS, to alpha subunits (Go, Gs, Gi1, Gi2, and Gi3) was decreased in the presence of MTX. Furthermore, reconstitution of Galpha with Gbetagamma dimer showed a reversal of the inhibition elicited by MTX. GDP/GTP exchange rate for Galpha subunits was significantly inhibited in the presence of MTX. MTX had no effect on the rate of GDP or GTP dissociation from alpha subunits. Also, the mastoparan-induced component of nucleotide exchange is not effected by MTX. These results suggest that MTX acts on Galpha subunits to modulate their interaction with guanine nucleotides, perhaps by stabilizing an empty state of the alpha subunit. Accordingly, MTX may disrupt the normal signal transduction pathways by inhibiting GTP binding to Galpha subunits and interfering with the GDP/GTP exchange.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1091-5818
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-44
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:articleTitle
Effect of maitotoxin on guanine nucleotide interaction with G-protein alpha subunits.
pubmed:affiliation
Department of Biology, Armstrong Atlantic State University, Savannah, Georgia 31419-1997, USA. ritin_khan@mailgate.Armstrong.edu
pubmed:publicationType
Journal Article